A hernia is an abnormal protrusion of an organ, tissue, or any anatomical structure through a forced opening in some part of the surrounding muscle wall. For example, if a part of the intestine were to protrude through the surrounding abdominal wall, it would create a hernia--an abdominal hernia.
Hernias occur in both males and females in the groin area, also called the inguinal region. In both sexes, the abdominal wall may be weak on both right and left sides a little above the crease in the groin. Hernias are found most frequently in males where the potential for weakness originates during the development of the fetus when the testicles are located inside the abdomen. Just prior to birth, the testicles "descend" and leave the abdomen and enter the scrotum, the sac that contains the testicles. In doing so, they push their way through the lower portion of the abdominal wall. Although the abdominal wall "closes" around the spermatic cord to which the testicle is attached after the testicles descend, the area remains slightly weakened throughout adult life. If a part of the intestines or other tissue within the abdominal cavity pushes through one of the weak spots, it forms a hernia--an inguinal hernia.
Before the piece of intestine or other abdominal cavity tissue, called the hernial mass, makes its way through the weak spot in the muscle, it must first push its way through the peritoneum, the membrane that lines the abdomen. The hernial mass does not tear the peritoneum, however. Thus, when the intestine protrudes, it merely takes the peritoneum with it and is covered by it. The peritoneal covering surrounding the piece of protruding intestine is called a hernial sac.
Inguinal hernias can be indirect space inguinal hernias or direct space inguinal hernias. An indirect space inguinal hernia occurs in the following manner. The lower part of the abdominal wall where such hernias occur, the inguinal region, is comprised of two layers, an inner layer and an outer layer. Each layer has a weak spot in it but the weak spots are not directly aligned with each other. The weak spots in each layer are positioned slightly apart from each other.
The weak spot in the inner layer is called the internal inguinal ring. In starting to form the hernia, the hernial mass begins protruding through this internal abdominal ring adjacent to the spermatic cord. To reach the weak spot in the outer layer, called the external inguinal ring, the hernial mass must move for a short distance toward the midline of the body between the internal layer and the outer layer of the abdominal wall. This passageway is called the inguinal canal. The hernia that is formed by a hernial mass that passes through the internal inguinal ring, the inguinal canal, and out through the external inguinal ring, is called an indirect space inguinal hernia.
There are two types of indirect space inguinal hernias, right and left. A hernia that is formed on the right side of the body just above the crease in the groin area is called a right indirect space inguinal hernia. In this case, the external inguinal ring is positioned medially approximately 30.degree.-60.degree. to the left of the internal inguinal ring. On the other hand, a hernia that is formed on the left side of the body just above the crease in the groin area is called a left indirect space inguinal hernia. In a left indirect space inguinal hernia, the external inguinal ring is positioned medially approximately 30.degree.-60.degree. to the right of the internal inguinal ring.
The second type of hernia is formed when the hernial mass stretches out or pushes through weakened muscle wall located proximal to the internal inguinal ring. This type of hernia is called a direct space inguinal hernia. Direct space inguinal hernias may form one or more years after a patient has had a repair of an indirect space inguinal hernia unless both areas are supported at the same time.
Traditional surgical repairs of both direct and indirect inguinal hernias have used the conventional external approach called reparative herniorrhaphy. Reparative herniorrhaphy requires laparotomy, an incision two to four inches in length made in the abdominal wall. The external approach uses a prosthetic patch that covers the outermost surface of the defect without lending any major immediate support to the defect itself or the surrounding muscle wall. Scarification of the covering and defect sufficient to allow resumption of unrestricted activities, occurs only after five to six weeks resulting in a lengthy postoperative recovery period with significant patient discomfort that requires considerable pain medication. In addition, when the external method fails to use a prosthetic device and relies solely on the patient's natural tissue for outlying support to the surrounding area, recurrence of direct space inguinal hernias is relatively high (5%). Further complications resulting from reparative herniorrahapy include infection and either a complete or partial wasting away (atrophy) of the testicles due to obstruction of the testicular blood supply.
In accordance with the method of the present invention, inguinal hernias are repaired using laparoscopic surgery. Laparoscopic surgery is less invasive, less traumatic surgery that involves visualizing the interior of the abdominal cavity using an illuminating optical instrument, a laparoscope, that is placed through a puncture orifice in the abdominal wall. Laparoscopic procedures have value as a diagnostic and operative tool for general surgery, as well as for gynecological surgery wherein such procedures are widely used. The effective use of laparoscopic procedures in the repair of inguinal hernias and the like has heretofore not been possible.
The instrument inserted into the body in a laparoscopic procedure is called a "trocar" and comprises a cannula or trocar sleeve (a hollow sheath or sleeve with a central lumen) into which fits an obturator, a solid metal rod with an extremely sharp three-cornered tip used for puncturing the muscle. The obturator is withdrawn after the instrument has been pushed into the abdominal cavity. The trocar sleeve remains in the body wall throughout the surgical procedure and various instruments used during laparoscopic procedures are introduced into the abdomen through this sleeve. Trocars are available in different sizes to accommodate various instruments.
The trocar sleeves used in laparoscopic procedures are pertinent to the present invention because they provide the pathway for insertion of the prosthetic device of the present invention into the abdomen. Representative diameters are 3, 5,10 and 11 millimeters with the 5,10 and 11 millimeters being employed most frequently in accordance with the present invention. While the use of a trocar in laparoscopic surgery is beneficial in that it results in only a small puncture wound in the patient's abdomen, the small diameter of the trocar also limits the size of surgical instruments and prosthetic devices which may be inserted in the trocar. The adaptation of laparoscopic procedures to the repair of inguinal hernias, therefore, requires the development of special surgical equipment and procedures.
The advantages of laparoscopic surgery include: simplifying the general surgery procedure so that it can be done on an outpatient basis; providing the surgeon the opportunity for viewing intra-abdominal viscera without laparotomy, a large incision made in the abdominal wall; using small puncture wounds as opposed to large incisions, lessening the trauma to anterior abdominal wall musculature; providing the surgeon with the ability to diagnose indirect inguinal hernias and direct inguinal hernias before signs and symptoms become advanced; determining incision sites for laparotomies when such incisions are appropriate; reducing both patient and insurer medical costs by shortening hospital stays; and reducing postoperative patient discomfort with recovery times measured in days as opposed to weeks.
Heretofore, indirect space inguinal hernias have been repaired by the traditional method including laparotomy of the abdominal wall and the external covering of the defect. Laparotomy is an extremely invasive procedure, requiring five to seven weeks for post-operative recovery. Moreover, preventative steps with respect to direct space inguinal hernias have not always been conventionally attempted during the repair of indirect space inguinal hernias resulting in a significant incidence of direct space inguinal hernias years after the initial occurrence. While the laparoscopic repair of inguinal hernias has been attempted using the transperitoneal approach with and without the use of prosthetic mesh, recurrence of direct space hernias remains a problem because the hernial defect has been closed with staples with no mesh used for support or a mesh patch has been used to fill the internal opening of the hernial defect without giving support to the direct space adjacent to the indirect defect.